BOSTON — That the Celtics are three games over .500 after 35 games despite having just one former All-Star (David Lee) on their roster is, in part, a testament to head coach Brad Stevens.

Yet Stevens certainly isn’t immune to criticism, and some low rumblings of dissent reverberated through Boston’s locker room Wednesday after the Celtics’ late collapse against the Detroit Pistons, their third loss in four games.

The topic of contention: Stevens’ varying lineup combinations, which have fluctuated all season as the Celtics coach searches for a successful in-game routine.

“I’m not going to blame just one thing, but we still don’t really have a rotation, like a set rotation,” point guard Isaiah Thomas said.

Thomas was asked what change he’d like to see in Stevens’ rotation.

“I don’t know. A set one?” he responded. “(One where) guys know when they’re going in and coming out. I mean, for the most part, I know my minutes, but it’s hard for some guys. But as a professional, you’ve got to be ready. You can’t put that on the coach.”

Thomas, Jae Crowder and Avery Bradley (when healthy) have been the three staples in Stevens’ rotation, as all are averaging more than 30 minutes per game.

Outside that, it’s been all over the place. Kelly Olynyk played just 12 minutes Saturday in a loss to the Brooklyn Nets but started and logged 34 minutes when the teams met again Monday. David Lee is averaging nearly 16 minutes per game but didn’t even play in Boston’s last two games.

Marcus Smart’s significant knee injury and minor injuries to Bradley and others partly are to blame for Stevens’ shakeups. But Thomas — who ironically was one of Boston’s most inconsistent players Wednesday, starting 1 for 15 but finishing hot for a team-high 22 points — noted not having a set routine can negatively affect a player’s on-court performance.

“Inconsistent minutes give you inconsistent play, so I think that’s tough for them,” Thomas said. “But if I was in that position, I would try to figure it out and do the best I possibly could. I think it’s a mental thing more than anything, because you’ve got to keep your mind right and stay ready.

“I mean, it’s been (35) games, and if this is how Coach is going to coach, you’ve got to be ready for it. You can’t put it on him. As players, we go out there and play. We’ve got to do our job.”

Thumbnail photo via Bob DeChiara/USA TODAY Sports Images

Thumbnail photo via Boston Celtics guard Isaiah Thomas (4) watches the action from the bench during the second half against the Brooklyn Nets at TD Garden.